Trial protocol: A parallel group, individually randomized clinical trial to evaluate the effect of a mobile phone application to improve sexual health among youth in Stockholm County

Background: Genital Chlamydia trachomatis infection is a major public health problem worldwide affecting mostly youth. Sweden introduced an opportunistic screening approach in 1982 accompanied by treatment, partner notification and case reporting. After an initial decline in infection rate till the mid-90s, the number of reported cases has increased over the last two decades and has now stabilized at a high level of 37,000 reported cases in Sweden per year (85% of cases in youth). Sexual risk-taking among youth is also reported to have significantly increased over the last 20 years. Mobile health (mHealth) interventions could be particularly suitable for youth and sexual health promotion as the intervention is delivered in a familiar and discrete way to a tech savvy at-risk population. This paper presents a protocol for a randomized trial to study the effect of an interactive mHealth application (app) on condom use among the youth of Stockholm. Methods: 446 youth resident in Stockholm, will be recruited in this two arm parallel group individually randomized trial. Recruitment will be from Youth Health Clinics or via the trial website. Participants will be randomized to receive either the intervention (which comprises an interactive app on safe sexual health that will be installed on their smart phones) or a control group (standard of care). Youth will be followed up for 6 months, with questionnaire responses submitted periodically via the app. Self-reported condom use over 6 months will be the primary outcome. Secondary outcomes will include presence of an infection, Chlamydia tests during the study period and proxy markers of safe sex. Analysis is by intention to treat. Discussion: This trial exploits the high mobile phone usage among youth to provide a phone app intervention in the area of sexual health. If successful, the results will have implications for health service delivery and health promotion among the youth. From a methodological perspective, this trial is expected to provide information on the strength and challenges of implementing a partially app (internet) based trial in this context. Trial registration: ISRCTN 13212899, date of registration June 22, 2017.